The objective of this proposal is to examine the interplay between biobehavioral risk status and the social context of parental caregiving variables on developmental competencies of four year old children born at varying degrees of medical risk. The theoretical framework used in this study is the transactional model, which posits that contact between organism and social context results in the alteration of both components within the system. The central hypothesis states that, Developmental delay in four year old children born at varying degrees of medical risk is best predicted by the number and interplay of biobehavioral risk factors and parental proximal and distal caretaking factors. The relative importance of biobehavioral risk factors and parental caretaking environment will be explored by contrasting children who were born with varying degrees of medical risk status conditions. Another objective of this study is to examine changes in maternal perception of health status, temperament ratings, and maternal self-esteem from the neonatal period to age four. The sample will include 188 children that had been followed longitudinally until age two and were divided into five medical risk status groups ranging from full-term medically and neurologically healthy infants and four groups of preterm infants; less than 33 weeks gestation, less than 1.5 kilograms grouped by healthy, sick, sick plus CNS disease, small for gestational age (SGA) medical risk status. Mothers of these children were equally divided into middle socioeconomic status (SES) and lower SES. Biobehavioral risk ratings taken from the neonatal period include NBAS cluster scores, difficult temperament ratings, maternal perception of health risk, and medical risk. Caretaking variable, assessed by home visits, and a laboratory assessment include the proximal variables: maternal personality and perception, caretaking environment, and parenting strategies used in interaction. Distal measures are SES, social support, family resources, stressful life events, and the physical environment. Developmental competency will be measured by the McCarthy Scales of Children's Ability, free play, mastery, and a problem solving interaction paradigm designed to measure competency. A multivariate design including hierarchical multiple regression will test the central hypothesis. By considering both biological and social environmental estimates this study will enable us to determine which infants re most vulnerable to developmental delay.